Physics math question

Im pretty bad at these physics math problems and our book doesnt go over how to do them very much so I was wondering if I could get some help..

The problem is The weight of the atmosphere above 1 square meter of the earth's surface is 100 000 newtons. If the density of the atmosphere were a constant 1.2 kg/m(cubed), calculate where the top of the atmosphere would be.

Okay so we have the weight of the atmosphere as 100,000 newtons, the density is 1.2 kg/m(cubed). We learned that the pressure of the atmosphere is 100,000 newtons per meter squared, or 100 kilo pascals.

There a special formula in our to calculate how high the atmosphere is based on the density or the pressure?

basically what you would want to do there, since you already know two of the dimensions of the volume(length=1m and width=1m), is figure out what the 100,000N is in kg and divide that by how many kilos it is per m^3. because you have a 1x1 square, the number of cubic meters will also be the height, because 1x1xY=Y